maintenance of gcc cross ports

Sun May 19 17:48:22 UTC 2019

I have a Raspberry Pi 3 model b. I use the LLVM toolchain to build the system but the GNU toolchain is required to build U-Boot. U-Boot uses global register variables and LLVM doesn't support this. sysutils/u-boot-pine64 does use aarch64-none-elf-gcc, for the same reason. The family is allwinner64 and that's set to use aarch64-none-elf-gcc. Here is an article explaining the feature U-Boot uses that's not in LLVM (the reason GNU is required for building it):

https://gcc.gnu.org/onlinedocs/gcc/Global-Register-Variables.html

Aarch64 is a Tier 2 architecture. The toolchain should have an active maintainer (the maintainer is listed as ports at FreeBSD.org). I've opened a bug report for the bugs in the Makefile. We should be using a newer toolchain or separate arm-none-eabi and aarch64-none-elf from powerpc64. I am guessing the Makefile bugs occurred because the original designer didn't intend on powerpc64-gcc being used for targets like arm-none-eabi and aarch64-none-elf. The patches you pointed out before don't even have any effect on the bare metal ports. The arm and aarch64 bare metal ports are the oddballs in the group. The difference being: powerpc64-gcc, aarch64-gcc, amd64-gcc, i386-gcc, mips*-gcc, and sparc64-gcc are all intended for, as you said Mark, alternate toolchain work with FreeBSD. These are not the official toolchains for FreeBSD and I can see why they don't have the same level of care as the official toolchain. But the side effect of this is arm-none-eabi-gcc and aarch64-none-elf-gcc receive the same level of support, though they are *required* to build most FreeBSD systems on those platforms.

- James Shuriff

-----Original Message-----
From: Mark Millard <marklmi at yahoo.com>
Sent: Sunday, May 19, 2019 11:46 AM
To: James Shuriff <james at opentech.cc>
Cc: ports-list freebsd <freebsd-ports at freebsd.org>; bapt at FreeBSD.org; jhb at FreeBSD.org
Subject: Re: maintenance of gcc cross ports

On 2019-May-19, at 07:40, James Shuriff <james at opentech.cc> wrote:

> I didn't/don't plan on touching binutils. Binutils is okay. I made new patches as well. What I'm really concerned with bringing up to date is aarch64-none-elf-gcc.

> The GNU toolchain is unfortunately required for building an Aarch64
> system

Are you specifically referencing contexts that need to build u-boot? (My guess is: yes.)

I've done buildworld buildkernel based on system clang and lld many times in the past, though not very recently. (I currently do not have access to the environment but will again, eventually.)

For aarch64 I'd mostly recently built for and used:

A) a Pine64+ 2GB (needs: sysutils/u-boot-pine64 )
B) an OverDrive 1000 (no u-boot build needed)

I've done amd64->aarch64 cross builds and self hosted ones for/on such. The OverDrive 1000 builds did not involve devel/aarch64-none-elf-gcc at all as far as I can remember.

> and is a prereq for a bunch of sysutils arm ports.

Yep.

Are there sysutils/u-boot-* 's that no longer build under gcc 6.4.0?
Other things?

> At worst we can do something like what's done with the lang ports gcc6, gcc7, gcc8. I've CC'd the maintainers so hopefully they can give us some input and we can come up with a solution.
>
> As for Makefile issues, this is only an issue for the arm-none-eabi-gcc and aarch64-none-elf-gcc ports because they have multiple hyphens. It's mostly a cosmetic issue. Each port has its own plist because gcc generates different headers depending on the platform so the PLIST TARGETARCH regex doesn't really affect all that much. There are some clang flags dependent on TARGETARCH but whoever wrote the aarch64-none-elf-gcc port must have known it wasn't working in the master because the check is in the bare metal port as well. The stripping out of all hyphens causes things like "gcc version 6.4.0 (FreeBSD Ports Collection for aarch64noneelf)". I use ${PKGNAMEPREFIX:C/-$//} for the comment and version and ${PKGNAMEPREFIX:C/-.*//} for TARGETARCH. The original regex for all of those is ${PKGNAMEPREFIX:C/-//g} and I'm sure you can see how that's a problem when there's multiple hyphens.

Thanks for the notes.

> - James Shuriff
>
> -----Original Message-----
> From: Mark Millard <marklmi at yahoo.com>
> Sent: Sunday, May 19, 2019 1:33 AM
> To: James Shuriff <james at opentech.cc>; ports-list freebsd
> <freebsd-ports at freebsd.org>
> Subject: Re: maintenance of gcc cross ports
>
> James Shuriff james at opentech.cc wrote on Sat May 18 12:29:22 UTC 2019 :
>
>> The powerpc64-gcc port and all the ports that use it as a master (aarch64-gcc, aarch64-none-elf-gcc, amd64-gcc, arm-none-eabi-gcc, i386-gcc, mips-gcc, mips64-gcc, and sparc64-gcc) are very old and use buggy makefiles. I would like to take over maintenance of these ports. Powerpc64-gcc uses an old version of gcc and the makefile is buggy. Certain variables use bad regular expressions thus don't do what they're supposed to do. I've fixed up the makefiles and made new plists with a newer version of gcc.
>
> Be aware that:
>
> /[ports]/head/base/binutils depends on devel/binutils via:
>
> MASTERDIR=${.CURDIR}/../../devel/binutils
>
> /[ports]/head/base/gcc depends on devel/powerpc64-gcc via:
>
> EXTRA_PATCHES+=
> ${.CURDIR}/../../devel/powerpc64-gcc/files/freebsd-format-extensions
> EXTRA_PATCHES+=
> ${.CURDIR}/../../devel/powerpc64-gcc/files/freebsd-libdir
> EXTRA_PATCHES+=
> ${.CURDIR}/../../devel/powerpc64-gcc/files/patch-gcc-freebsd-mips
>
> The maintainer is listed as: bapt at FreeBSD.org but the activity tends to be jhb at FreeBSD.org . There are other, more overall FreeBSD toolchain efforts that these various ports are tied to. That may constrain what can be done when. You would probably need to consult with these folks about any changes.
>
> I use these ports for doing alternate toolchain buildworld buildkernel activities, including using, say, devel/powerpc64-gcc on a powerpc64 machine to self host with more modern tools than gcc 4.2.1 based ones.
> As I understand, being in devel/ instead of lang/ for gcc tools is tied to being constructed for the system-building activities instead of for general use.
>
> You might want to show your Makefile updates so that that the problems are fully explicit.
>

===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)

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